We propose a 2-arm, parallel group, randomized controlled trial to test the efficacy of adding two innovative ?wise? social psychological interventions?growth mindset and self-affirmation?to 6-month family-based, group behavioral intervention for weight control in children with obesity, to reduce body mass index trajectory over 12 months, compared to the behavioral intervention alone. A total of 200 8-12 year old children with obesity (BMI ? 95th percentile) will be randomized to the two conditions. All children will participate with their parents in a usual care six-month, family-based, group, behavioral weight control program. In addition, families randomized to the social psychological intervention condition will receive two innovative ?wise? social psychological interventions?growth mindset and self- affirmation?strategically selected and timed to enhance the behavioral intervention. There remains a great need for innovative approaches to increase and sustain weight loss among children with obesity. Weight control interventions may be limited in their success in many children in part because of psychological barriers and threats they face when attempting to manage their weight. One of the most exciting recent breakthroughs in the behavioral sciences is the development of seemingly small but ?wise? interventions?typically consisting of brief exercises and messages grounded in social psychological science?that produce powerful and positive long-term changes in behavior. These interventions help people flourish by altering the ways in which they think about themselves and their environments. We propose that two of these interventions with some of the strongest empirical support will be particularly useful in creating the right psychological landscape for more consistent and successful behavior change and weight loss. A growth mindset of body weight creates the vital belief that success is possible with effort and hard work. Self-affirmation helps people cope with stereotype threat by allowing them to focus on other sources of self-worth, thus freeing them from the distraction and anxiety of possibly confirming the stereotype that they won't succeed. As a result, this approach has the potential to substantially improve treatment outcomes and reduce the concurrent and future morbidities that accompany childhood obesity. Measures will be collected at baseline, 3 mos, 6 mos (end of the behavioral treatment), and 12 months (6 months after the end of treatment). Primary Hypothesis: Compared to children randomized to receive the usual care family-based, group behavioral weight control program alone, children randomized to receive the usual care family-based, group behavioral weight control program plus the wise social psychological interventions will have a significantly attenuated BMI trajectory over 12-months.